Linear Standard Model extensions in the SMEFT at one loop and Tera-Z
Abstract
Linear Standard Model (SM) extensions, defined as new particles that can couple linearly to SM fields, form a motivated and finite set of simplified models for exploring phenomenology Beyond the SM (BSM). Heavy BSM particles may be integrated out to obtain their low-energy effects in the SM Effective Field Theory (SMEFT) parametrised by the Wilson coefficients of higher-dimensional operators. We compute and map the dimension-6 SMEFT operator structure of all scalar and fermion linear SM extensions up to one-loop order, thus extending the existing tree-level dictionary of results. Explicit analytic matching expressions for the Wilson coefficients are provided as both Python and Mathematica code in a GitHub repository accessible through links embedded in our main table for each coefficient and within a Python package. We apply our map to highlight the sensitivity to heavy new physics of a -pole run at a future Tera- factory; at one loop, with unit couplings, all linear SM extensions can be indirectly probed by electroweak precision measurements up to TeV.
Cite
@article{arxiv.2412.01759,
title = {Linear Standard Model extensions in the SMEFT at one loop and Tera-Z},
author = {John Gargalionis and Jérémie Quevillon and Pham Ngoc Hoa Vuong and Tevong You},
journal= {arXiv preprint arXiv:2412.01759},
year = {2025}
}
Comments
32 pages, 10 tables, 4 figures. v2: Corrected missing tree contribution to tree+RGE bar chart plots; version published in JHEP